The purpose of this lesson is to visually illustrate the negative effects on the environment of dumping toxic wastes into the soil by constructing a soil simulator.

Connection to the Curriculum: Geography, Science

4 Explain how humans and the physical environment impact and influence each other

4 The physical and human characteristics of places
14 How human actions modify the physical environment?

Procedure:

Students should have a prior understanding of past history of mankind and the use or abuse of natural resources, lessons on soil components, lessons on water, runoff and erosion. Introduce the geography theme of human-environmental interaction.

1. Divide students into partner groups and introduce "Dirt Alert" scavenger game. Give each group a game board with definitions and an envelope with cut-up vocabulary words. The objective of the game is to correctly match-up the vocabulary words with the corresponding definitions. Students raise hands when they think they have the correct answers. The first team with all the correct answers wins the game.
2. Divide the class into groups of 4-5 students. Explain steps: start at the edge of the pan and spread a thin layer of modeling clay over 1/3 of the pan, put humus material on top of clay, cover humus with layer of sand "A", cover sand "A" with layer of sand "B". Review soils used in construction of the model. Explain that sand "A" represents soil that has been contaminated with toxic wastes.
3. Pass out water bottles and explain that the water represents rainfall. Remind students to observe carefully. Have students slowly drip simulated rain onto the soil model. Orally review the results and record on an experiment sheet.